Design Of High Performance Dual Channel Full H-bridge DC Stepper Motor Driver

At present,with the continuous development of power electronic technology,motors have gradually replaced traditional internal combustion engines and are used in large equipment such as automobiles,ships,submarines,and aircraft.In particular,the market share of civilian electric vehicles continues to rise,and the market has put forward higher requirements for the function,power,efficiency,control accuracy and control intelligence of the motor.This makes the development and design of smart power motor drive chips a hot spot in the current research field of smart power integrated circuits.In this paper,based on the Shanghai Huahong Hongli(HHG)0.35μm BCD process,a DC stepper motor driver chip based on a double H-bridge structure is designed,which has a wide operating voltage range of 2.5V to 12 V,peak drive current 2.2A,It can drive the stepper motor intelligently,and has the characteristics of multiple state protection for the motor.The chip integrates step current control register,dual-mode controller circuit,bandgap reference circuit,high-voltage LDO circuit,H-bridge drive circuit,onchip capacitor high-voltage charge pump circuit with synchronous rectification function,over temperature,over current,over voltage,Undervoltage protection circuit,current controller with mixed attenuation function and 8 N-type DMOS power devices.The onresistance of the H-bridge power device is 300mΩ at room temperature of 25°C.This paper proposes a novel logic control scheme that can accurately and conveniently control the stepper motor current.Through specific circuit design,the goal of precise control of the motor drive current is achieved.Compared with the traditional two-phase four-wire stepper motor driver,this logic control scheme can control the speed,steering and step length of the stepper motor using only four control signals.Through the mode selection,a variety of subdivision driving methods can be realized in full step,half step,1/4 step,1/8 step,1/16 step,1/32 step,which greatly simplifies the number and complexity of external control signals.The mixed attenuation control mode designed in this paper can adjust the attenuation rate of the motor winding current by adjusting the external resistance value of the XDECAY pin,and the current attenuation rate has a linear relationship with the resistance value.This design adjusts its current attenuation rate according to the winding size of different motors,which helps to improve the motor jitter caused by PWM and improve the control accuracy.Simulation and test results show that the main parameters of the drive current output capability,current control,charge pump output voltage,and LDO output voltage designed in this paper meet the design index requirements.Practical application shows that the driver chip designed in this paper can drive the motor forward and reverse,fast and slow braking and other functions,and can accurately adjust and control the speed by controlling the current of the stepper motor.